From the 2018 International Residential Code unless otherwise indicated.
Openings from a private garage directly into a room used for sleeping purposes shall not be permitted. Other openings between the garage and residence shall be equipped with solid wood doors not less than 1 3/8 inches (35 mm) in thickness, solid, or honeycomb-core, steel doors not less than 1 3/8 inches thick (35 mm), or 20-minute fire-rated doors, equipped with a self-closing or automatic-closing device.